SAFACTIVE FILTER - COMAR CONDENSATORI SpA

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Led interface The easy basic interface allows with leds to understand the system operation and the changing internal state. In particular the green led monitors the right function of the system during the compensation, and the startup procedure, lighting in two different way to show the “pre-charge” operation and the “contactor on” operation. The four red leds are monitoring the fault that occurs in the filter: ‣ Power supply out of the rated range (“Supply voltage”) ‣ Fault of the contactor or of the inverter section start-up (“Contactor”) ‣ Fault of the internal temperature (“Temperature”) ‣ Fault on the inverter section (“Inverter”) Active Filter performances Harmonic pollution: in the following figure there are two waveform of the absorbed current of a typical non linear load before and after the filtering. In the upper wave a 42 Arms current with THD i of 73% is filtering and it results the lower wave with 38 Arms and a residual THD i of 8%. Absorbed current of a non linear load before and after the filtering 10 http://www.comarcond.com
Power factor correction: It is possible to select on the regulator board the possibility of a partial power factor correction while filtering with a good final result. Voltage and current before the filtering (left waveforms) and with the filter with both the operation of harmonic pollution and power factor correction (right waveforms) In the two pictures it is possible to see the initial displacement between the voltage and the current of a non linear load before filtering that is with the current affected by harmonics. In the right figure it is possible to see that after the filtering the current is not affected by harmonics and it is shifted to the left nearer the voltage waveform, improving the power factor. Current limit: When the harmonic current to be compensated is higher than the rated current of the filter connected, the equipment doesn’t stop its operation, but gives to the network a well shaped compensated current up to the rated limit. This permits to have compensation of the harmonic current even if not in the optimum mode, but without cutting off the compensating current at the rated value thus avoiding additional harmonics. Sizing SAF To understand which is the right size of the filter Comar Condensatori S.p.A. it is necessary to take some measurements on the installation in order to select the right reactive power of the fundamental component and of the other harmonics. For this measurement it’s necessary an instrument that can measure the harmonic components (oscilloscope; data logger etc.). It is so possible to have a series of value of current of the fundamental component (I1 50Hz ) and of the other harmonics as in the next example: I1 50Hz =30A, I5 250Hz =10A, I7 350Hz =5A, I11 550Hz =3A, I13 650Hz =1A, ..... or, that is the same, the value of the parameter of the harmonic current distortion: THD (Total Harmonics Distortion =X % THD is a number that represents the harmonic pollution and it mathematically given by the next expression where I means the rms value of the fundamental current: THD := I 2 2 2 + I + 3 I + 4 I + 5 ...... I http://www.comarcond.com 11
Page 1 and 2: UNI EN ISO 9001:2000 C E R T I F MA
Page 3 and 4: Index • Introduction ............
Page 5 and 6: The presence of harmonic current in
Page 7 and 8: Active Filter block schematic • I
Page 9: flows to the load from the negative
Page 13 and 14: The SAF system The active filter ha
Page 16: Grafica Junior - Tel. 051.733020 CO

SAFACTIVE FILTER - COMAR CONDENSATORI SpA

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